I have what appears to be basically the exact same trailer as you, and I have two cents to give you about hauling a tractor on it. If your trailer is like mine, it's a 16', tandem axle, utility trailer with 7000 lb GVWR. The cross-members on the frame are perhaps 2x3" angle iron, at something like 3' spacing. When I got my tractor, I thought, "7000 lbs GVWR - 1600 lbs trailer weight - 4000 lbs tractor weight = I'm 1400 lbs under, I'm good!" Not so. First of all, as you have suggested, the gate will not load the tractor without being damaged. It did it a few times, but I could see that it was going to give out. I eventually put some jack stands under the middle of it to give it some extra support, but even that was dicey. The real problem, however, is that a utility trailer rated for 7000 lbs is just not made to carry all 7000 lbs concentrated on as small an area as a vehicle creates. If you think about it, worst case scenario is that your tractor's axles are right over two cross-members, which means that each little piece of angle iron is carrying half the tractor's weight. If you look at car-haulers vs. utility trailers in a similar size and GVWR, you'll see that the car-haulers have different construction that is designed to handle the high point-load that a vehicle's tires make; utility trailers are not.
Bottom line: I wouldn't tow a tractor on a utility trailer.
